Collaborative research: Controls affecting greenhouse gas fluxes in restored and natural tidal wetlands

1133074（Jaffe）。温室气体（GHG）排放的一氧化二氮（N2 O），甲烷（CH 4），二氧化碳（CO2）在很大程度上是未知的河口湿地地区。人工湿地是净辐射汇的概念还没有得到验证的沿海湿地和许多研究告知这一假设没有考虑N2 O通量。氮和碳物种之间的河口湿地，大气和邻近的河流将被测量沿着水文周期，盐度和缓解梯度和缩放到生态系统的水平。涡度相关技术将是用于约束CO2和CH 4通量估计的主要方法。通量室和地下溶解的CH 4，N2 O和无机碳测量结合这些通量的建模/缩放将被用来确定N2 O通量，并通过比较CO2和CH 4通量从两种技术验证这种技术的准确性。通过潮汐流从选定的沼泽中溶解的有机碳、溶解的无机碳和溶解的氮的净损失也将在这些沼泽的点入口处进行监测。 并行光合作用测量芦苇，C3植物，和米草属，C4植物，将占这些物种的CO2交换。这种气体交换是由生物物理、水文和水化学驱动因素驱动的。半咸水沿海湿地的碳固存与同一系统的CH 4和N2 O排放之间的平衡仍不清楚。因此，监测和模拟这些驱动因素对整体温室气体交换的影响，在个别工厂和生态系统的水平，将有助于评估这些控制和规模的温室气体通量在城市潮汐湿地的生态系统水平。将采用自下而上的方法（通过测量和PI开发的基于过程的模型）和自上而下的方法（通过涡流通量测量）相结合的方法，以解决生物圈-大气温室气体交换的不同驱动因素，并能够扩展到生态系统和区域层面。这项研究将提高我们对城市潮汐沼泽地沿海湿地温室气体动态的理解。 这些新的见解将与草地环境中心的许多游客分享，包括加州。每年有15，000名学童参加关于城市河口的各种讲习班和教育活动。 这项研究还将包括为路易斯·斯托克斯少数民族参与联盟（LSAMP）的学生提供资金，该学生将被聘为暑期实习生，以协助研究生进行实地数据收集和外联活动。此外，自2003年以来，每四年，草地环境研究所（MERI）与政府机构和大学合作，赞助草地研讨会，200多名研究科学家，学生和专业人士的聚会，讨论和解决城市河口的环境问题。该项目还将培训两名研究生，一名在罗格斯大学，一名在普林斯顿大学。这项研究的结果将通过会议报告和同行评议的期刊文章传播。实验设置和生成的数据将被两个PI用于增强学生在研究生和本科生实验中的实践经验。这项研究将产生一个丰富的数据集，由MERI维护，这将是非常有价值的温室气体建模科学界

1133074 (Jaffe). Greenhouse gas (GHG) emissions of nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2) are largely unknown for estuarine wetland areas. The notion that constructed wetlands are net radiative sinks has not been verified for coastal wetlands and many of the studies informing this hypothesis have not considered N2O fluxes. Fluxes of nitrogen and carbon species between estuarine wetlands, the atmosphere, and an adjacent river will be measured along a hydroperiod-, salinity-, and mitigation gradient and scaled to the ecosystem level. The eddy covariance technique will be the principal method used to constrain estimates of the CO2 and CH4 fluxes. Flux chamber and subsurface dissolved CH4, N2O, and inorganic carbon measurements combined with modeling/scaling of these fluxes will be used to determine the N2O fluxes and verify the accuracy of this technique by comparing CO2 and CH4 fluxes from both techniques. Net losses of dissolved organic carbon, dissolved inorganic carbon, and dissolved nitrogen from selected marshes via tidal flow will also be monitored at point inlets to these marshes. Concurrent photosynthesis measurements of Phragmites australis, a C3-plant, and Spartina spp, C4-plants, will account for the CO2 exchange by these species. This gas-exchange is driven by biophysical, hydrological and hydrochemical drivers. The balance between carbon sequestration in brackish coastal wetlands and CH4 and N2O emissions from the same systems remains unclear. Thus, monitoring and modeling the effects of these drivers on overall greenhouse gas exchange, at the individual plant and ecosystem-level, will help assess these controls and scale GHG fluxes in urban tidal wetlands to the ecosystem level. A combination of bottom-up approaches, via measurements and process-based models developed by the PIs, and top-down approaches via eddy flux measurements will be used to tackle the different drivers of biosphere-atmosphere GHG exchange and enable scaling to ecosystem and regional levels. This research will enhance our understanding of coastal wetland GHG dynamics in urban tidal marshes. These new insights will be shared with the many visitors of the Meadowlands Environmental Center, including ca. 15,000 schoolchildren who participate in a wide range of workshops and educational activities about urban estuaries each year. This research will also include funding for a Louis Stokes Alliances for Minority Participation (LSAMP) student to be hired for a summer internship to assist the graduate students in field data collection and outreach activities. In addition, every four years since 2003, Meadowlands Environmental Research Institute (MERI) has collaborated with government agencies and universities to sponsor the Meadowlands Symposium, a gathering of over 200 research scientists, students, and professionals, to discuss and address environmental issues of urban estuaries. The project will also train two graduate students, one at Rutgers University and one at Princeton University. Results from this research will be disseminated via conference presentations and peer-reviewed journal articles. The experimental setup and data generated will be used by both PIs to augment hands-on experiences for students in their graduate and undergraduate experiments. This research will yield a rich data set, maintained by MERI, that will be highly valuable to the green-house-gas modeling scientific community